Indicating device



Malyv 27, 1930. A. A. THOMAS INDICATING DEVICE Original Filed Aug. 24, 1925 N fwnw A15 limited space necessitates narrow Patentes May 27, lese I ADOLPH A. THOMAS, OF NEW YORK, N. Y.

NDCATING DEVICE Original application led August 24, 1925, Serial No. 51,915. Divided and this application. filed March 20,

1929. Serial My invention is for an indicator of novel construction particularly adapted for use in variable condenser and other Aelectrical tuning instruments. The characteristic feature of this invention is a spiral scale covering more than 360 degrees, which enables me t0 graduate the scale with more and Wider divisions than are possible on the circular scales of prior dials. 1n condenser dials or drums heretofore used in radio receivers, the reading can not possibly cover more than one full turn of the dial shaft (and usually only half a turn), so that the maximum scale length available is 360 degrees. Manifestly, this divisions and makes it difficult to print all the stations wave lengths or frequencies on the dial. Furthermore, stations on short wave lengths are crowded at the low end of the dial and are difficult to separate. All these and other difficulties are avoided in my new indicator, where the spiral scale may be extended to any practical limit for calibration with widely spaced marks.

The novel features and advantages of this invention will be understood from a description of the accompanying drawings, in which- Fig. 1 shows a face view .of cator embodying my invention,

ing panel being omitted Fig. 2 represents a vertical section on line 2-2 of Fig. 1;

Fig. 3 is a section on and l f Fig. l is a fragmentary view similar to Fig. 1, showing a different position of the indicating shutter. 4 I

A disk or dial 10 is formed on its front face with a spiral groove or slot `12, which begins at 13 and ends at 14C, these two points being 7 20 degrees of rotation apart. Along the spiral groove 12 is marked a spiral scale 15, which is arbitrarily divided into 100 points.

a spiral indithe supportline 3-3 of Fig. 1;

The disk 10 is fined on a shaft 16, which is supposed to be connected to the movable niember of a tuning device in proper gear ratio, so that it takes more than one turn of disk 10 to adjust the tuning device from minimum to maximum value. The most common form of Athe scale.

tuning device used in radio receiving nowadays is a condenser or a gang of condensers. The shaft 16 extends through a support 17, which may be the front panel of a radio cabinet, and is operated by means of a knob `18. The panel 17 has a window or sight opening 19. Back of this window are mounted two oppositely arranged guides 20, which are secured in properly spaced relation on the back .of the panel by screws 21, or otherwise. The guide pieces 2O are formed with parallel olfset flanges 22 between which slides a shutter 23 carrying a pin 24. This pin projects rearwardly into the spiral groove 12. The shutter 23 is at its lower edge formed with a pointed projection 25 arranged centrally of the scale window 19. The projection 25 acts as an. indicating pointer and may be appropriately colored for an easy reading of the scale.

When the dial 10 is in normal or zero position, as indicated in Fig. 1, the slidable shutter 23 is in its uppermost position, and the pointer 25 indicates the .zero mark on the scale. If we now imagine the knob 18 turned clockwise, as indicated by arrow 26 in Fig. 1, the shutter 23 will be automatically adjusted into aposition where the pointer 25 always stands over the proper mark .on the spiral scale 15. ln other words, as the spiral edge of scale 15 turns in toward the center of the disk, the spiral groove 12 gradually moves the shutter 23 radically and maintains it in proper alignment with the changing periphery of rl`he innermost position of shutter 23 is reached in this instance when the dial has received two complete turns in a forward direction.v llVhen the dial 10 is turned 'backward, the indicating shutter 23 is pushed up in a radial direction into the correct indicat- 4 ing position. lt is obvious that the spiral scale 15 can be extended over a greater length than two turns of the dial, and the construction illustrated is to be considered merely as au example of how this feature of my invention may be embodied in practical form.

A though l have shown and described a specific construction, I do not consider my invention limited to the details set forth.

Changes and modifications will probably 100 occur to others within the scope of the appended claims. rlhis case is adivision of my copending application Serial Number 51,915, filed August 24, 1925.

I claim as my invention:

1. Dialing means for radio use including a rotatably mounted dial'having progressively numbered divisions arranged thereon in a plurality of spiral turns about the center of mounting, al spiral abutment rotatable with the dial coextensive with the spiral turns and having substantially the same pitch as that of the spiral turns, a guide and an indicator mounted in the guide engaging the abutment, said indicator having radial movement across the dial adapted to abut upon each indicating number of said divisions.

2. Radio dialing means including a rotating dial having station indicating characters thereon arranged in progressively increasing value throughout a plurality of complete spiral turns surrounding the dial center, a spirally formed abutment rotatable with the dial, the same being coeXtensive with and of substantially the same pitch as said spiral turns of characters7 a guide, and an indicator mounted in the guideV engaging the abutment, said indicator having movement radially across the dial due to said abutment and adapted to abut upon and follow the spiral yturns ofV said characters throughout the several rotationsof the dial.

8. A radio dialing mechanism including a condenser shaft, a dial-plate affixed-to and revoluble with said shaft and provided with a continuous spiral abutment having a plurality of turns around the center of dial rotation, said dial-plate having indicated divisions arranged thereon in a spiral`V or scroll corresponding to that of the abutment, and an indicator mounted to traverse the dial radially, and engaging the spiral abutment of said dial plate, said indicator following in its radial movement the spirally arranged indicating divisions. Y l

4. Dialing mechanism including a condenser-shaft, a mounted dial-plate adapted to ro- -tate in the rotation of the shaft, said dialplate,A having numbered divisions denoted thereon arranged in a spiral or scroll, the numbers of said divisions increasing in value toward the center of rotation, a spirally formed abutment on the face of the dialplate, an indicator overlying the dial and engaging the abutment, the same adapted to be moved radially of said dial, and a mounting in which the indicator is guided.

5. Radio dialing mechanism with the shaft of a condenser, fixed with respect to said shaft to rotate therewith, and having a series of equally spaced characters on its face to indicate station settings and arranged in a plurality of spiral turns, a spirally arranged abutment rotatable with the dial-plate, the same corincluding a dial-plateV responding in direction and pitch to said turns, being substantially coexten'sive with the latter, a guide, and an indicator mounted in the guide engaging the abutment and eX- tending between a given turn of said abutment and a corresponding turn ofthe said plurality of spiral turns of characters, following the spiral turns in the rotation of said dial-plate.

6. In a dial mechanism, the combination of a rotatable condenser shaft, a mounted dial rotatable with the shaft at the same rate of the spirally arranged'divisions, a guide, f"

and an indicator mounted in the guide overlying' the dial and engaging and movedV by the said abutment.

7. ln a dial mechanism, the combination with a condenser shaft, a dial-plate affixed thereto and having a spirally cut groove therein, a dial on said plate having numbered divisions arranged in a spiral conforming in pitch and direction to the 'said groove, a guide, and engaging in the groove and adapted to be moved across the dial in a radial direction.

8. Radio dialing means including a dial adapted to rotate having a series of characters on its face each of a different reading for indicating separate station settings arranged in a continuous spiral turn about the center of the dials rotation, an indicator, means to rotate the dial, and a part on the dial engaged by the indicator and fashioned to advancethe latter radially across the dial at a rate of travel in proportion to the advance of the readings of the said characters on the dial during rotation, and guide means for such indicator. Y.

9. Radio dialing means including a dial adapted to rotate having a row of characters of constantly increasing value arranged thereon about its center of rotation in a number of spiralturns, an indicator and a mounting therefor, and a part on the dial with which the indicator engages and by which the latter is advanced through a given uniform distance `of' travel in a full revolution of said dial, said part also adapted to continuously and uniformly advance said indicatorfduring other dial rotations in the same direction.

and an indicator mounted linthe guide "izo 10. ln combination, a revoluble radio dial Y,

having numerals arranged thereon in a plurality of spiral turns about a common point and disposed in continuous substantially regular spaced relation throughout, the same constantly increasing in value and all said numerals being arranged in grouped columns arranged radially of said dial, an indicator, ter moves relatively to said scale to indicate a support including a guide for the indicator, the correct reading thereof. said guide lying radially of said dial, and 16. A radio receiver having a front panel a part on the dial with which the indicator provided with a sight opening, an indicator engages operable in the rotation of the dial movable vertically behind said opening, a 70 for moving said indicator radially across said rotary shaft projecting through said panel, dial. a disk mounted on said shaft behind. said 11. In combination, a revoluble dial havpanel and carrying a spiral scale visible ing numerals arranged thereon in increasing through said opening, said disk having a value throughout a plurality of spiral turns spiral groove running with said scale, and v75 about a common point, all said numerals bea lug projecting rearwardly from said. indiing grouped in substantially evenly spaced Gator into said groove, whereby the indicator columns arranged in radial lines 0n Said dial, moves relatively to said scale to`1ndicate the the numerals of the separate columns incorrect reading thereof. creasing in value consecutively by the addi- ADOLPH A- THOMAS 80 tion of a chosen constant, an indicator, a support including a guide for the indicator, said guide lying radially of said dial, and a part on the dial with which the indicator engages operable in the rotation of the dial 35 flor moving said indicator radially across said ial.

12. In combination with the shaft of a radio condenser, a dial having station indicia arranged in spiral order thereon, an indicator 90 adapted to move across the face of the dial in a substantially radial direction, a support including a guide for the indicator, said guide lying radially of said dial and an abutment 3o on the dial with which the indicator engages, 95

one of the two elements first named operatively engaging said shaft and adapted in the rotation of the latter movable one with respect to the other. 13. In combination with the shaft of a 100 radio condenser, a dial having station indicia arranged thereon in spiral order, an indicator adapted to move across the face of said dial toward and away from the center thereof, and cooperating means on said dial and 105 indicator for guiding the movements of the latter, one of the two elements first named being connected to said shaft, whereby rotation of the shaft causes one of said elements to move with respect to the other. iio

14. A radio receiver having a front panel provided with a sight opening, an indicator movable vertically behind said opening, a rotary shaft projecting through said panel,

a disk mounted on said shaft behind said 115 c panel and carrying a spiral scale visible through said opening, and an operative connection between said disk and said indicator whereby the latter moves relativelyto said scale to indicate the correct reading thereof. 15. A radio receiver having a front panel provided with a sight opening, a pair of vertical guides secured to said panel on either 6D side of said opening, an indicator movable 125 in said guides behind said opening, a disk mounted on said shaft behind said panel and carrying a spiral scale visible through said opening, and an operative connection between said disk and said indicator whereby the lat- 130 

